Divergent Routes to Chiral Cyclobutane Synthons from (−)-α-Pinene and Their Use in the Stereoselective Synthesis of Dehydro Amino Acids

Abstract

Several polyfunctionalized cyclobutane derivatives have been synthesized using commercial (-)-alpha-pinene and (-)-verbenone as chiral precursors. Thus, oxidative cleavage of these compounds by using ruthenium trichloride afforded quantitatively (-)-cis-pinonic and (-)-cis-pinononic acids, respectively, without epimerization. These products were converted into several types of aldehydes, which are the key intermediates in the synthesis of cyclobutane dehydro amino acids via Wittig-Horner condensations with suitable phosphonates. These reactions are highly stereoselective, affording exclusively (Z) isomers, stereochemistry being assessed by NMR experiments. The obtained dehydro amino acids are polyfunctionalized molecules useful for the synthesis of other alpha-amino acids, with additional chiral centers, whose configuration must be induced by the chirality of the terpene employed as a precursor.

Online atmospheric pressure chemical ionization ion trap mass spectrometry (APCI-IT-MS<sup>n</sup>) for measuring organic acids in concentrated bulk aerosol – a laboratory and field study

“…Both acids are regarded as representative compounds formed from monoterpene oxidation in the boreal forest atmosphere. Cis-Pinonic acid (Sigma-Aldrich, 98 % purity) was purchased as a commercially available standard, cis-Pinic acid is a self-synthesized standard (Moglioni et al, 2000). Zero air (hydrocarbon free) was purchased from Westfalen AG.…”

New Сhlorin-Terpene Conjugates: Synthesis, Photoinduced and Dark Cytotoxicity

“…[16] Chlorin terpene derivatives (3-7) were obtained by interaction of the activated carboxyl group of terpene acids with aminochlorin. The initial acids were: myrtenic, [17] 3,3-dimethylbicyclo[2.2.1]heptane-2-carboxylic, [18] cis-pinonic, [19] cis-pinononic, [19] and 2,2-dimethyl-3-(2-oxopropyl)cyclopropyl acetic acids [20] (Figure 1). Activation of the carboxyl groups of the terpenic acids was done using DCC.…”

“…In the chemical structure of these compounds there is a fragment of cis-pinonic acid which is easily derived from verbenone. [11][12][13] It can be assumed that the addition of the terpene moiety can improve the interaction with biological membranes compounds, enhancing the photosensitizing effect of the compound as a whole.…”

Synthesis and characterization of peroxypinic acids as proxies for highly oxygenated molecules (HOMs) in secondary organic aerosol

“…Pinic acid was synthesized using a similar procedure described by Moglioni et al (2000). 2.84 g pinonic acid was dissolved in 50 mL dioxane.…”